JPS60158966A - Method and device for controlling level of molten steel in continuous casting mold for multi-chamber continuous castingplant - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a continuous casting mold having at least two common tundishes, in particular two molds having a billet cross-section and vibrating synchronously. The present invention relates to a method for controlling the level of molten steel in the mold of a multi-chamber continuous staining plant having a continuous casting mold in which the strand is withdrawn by means of a synchronous drive and an apparatus for carrying out this method.

<Prior art> In a steel mill with a charging capacity of 150 tons or more,
It is difficult to cast strands with small cross-sections, especially billet cross-sections. This is because the strand cross section is small.
This is because the casting time per 1,000 yen is made extremely long, resulting in a large drop in charge and temperature drop in the tundish.

In order to prevent this, it is known to equip the ladle or tundish with a heating device, but this increases energy consumption and is uneconomical. Furthermore, it is known to construct continuous casting plants with a large number of side-by-side strands, with mold vibrators and pullers for these strands making it possible to create large strands 'r'.
Along with the 1111 interval, a large tandish is required.

This results in a considerable distance from the molten steel from the ladle outlet to the tundish outlet, which also results in an undesirable temperature drop.

Devices are known in which adjacent strands with a billet cross-section are pulled out of the mold by individually driven outer pulling rollers, the drawing rollers being driven synchronously (West German patent DE-A-3029990). . However, control of the final drawing speed is a problem in such devices. This is because pouring from the tundish involves pouring the same amount of molten steel into each mold to prevent wear and deposits on the outlet, and as a result, the molten steel level in the molds varies.

OBJECT OF THE INVENTION The present invention avoids these drawbacks and difficulties and creates a method in which the molten steel level in each of a number of molds can be kept at the same level and yet the entire strand can be drawn out synchronously. The purpose is to confront this issue.

<Configuration 1 of the Invention, Effects> According to the present invention, the above problem is solved by detecting the molten steel level of one continuous casting mold, and thereby detecting the change in the drawing speed of the entire casting strand caused by four continuous casting molds. While compensating for the deviation in the molten steel level from the set value, it is possible to solve the deviation in the molten steel level in other continuous casting molds by controlling the amount of molten w4 flowing into the mold.

A device for implementing this method for controlling the level of molten steel, comprising at least two adjacent continuous casting molds with a common tundish, in particular having a billet cross-section,
An apparatus having two synchronously vibrating continuous casting molds with a synchronous prime mover for the casting strands emerging from the molds and with a strand guideway arranged below said molds is characterized in that The mold is equipped with a molten steel level detection device of 41 m to detect the molten steel level, and the inflow of molten steel from the tundish to one mold of the continuous casting mold is formed by free fall through a calibrated outflow nozzle, and from the tundish to the other mold. The inflow of molten steel into the mold is controlled by a plug or sliding plug, and a molten steel level detection device in the mold placed below a calibrated outflow nozzle is connected via a control line to a drive device that drives the drawing rolls. , is characterized in that the molten steel level detection device for other molds is connected to the control device for the plug or sliding plug via a connecting line.

The invention has the particular advantage for continuous casting plants designed as bloom casting installations that it is possible to cast two strands with billet cross section per bloom strand. In this case, the drawing rollers of the strand guide are advantageously formed as one piece extending over the casting strands of the continuous casting molds arranged side by side, in other words rollers for the drawing of strands with a bloom cross-section. can be utilized for the drawing of two adjacent strands with billet cross-section.

Advantageously, in adjacent strands, along the strand guide path between the casting strands, at right angles to the rollers, a radiation heat protection shield is provided, this radiation heat protection shield serving as a hollow cooling plate through which water flows. is formed.

A particularly simple constructed radiation heat protection shield is characterized in that it is designed as a widely dissipating fountain.

<Example> Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments.

The continuous casting apparatus shown in FIG. 1.2 for selectively casting strand-shaped castings with a bloom or billet cross section has a tundish (distribution vessel) 1, also called an intermediate vessel, above which the pouring process is carried out. 1 dollar 2 is carried in the position.

The molten steel flowing into the tundish 1 from the ladle 2 and flowing out from the tundish 1 reaches a plurality of molds 3, 3', etc. arranged side by side, and these molds are each fixed to a flange 4 that vibrates in the vertical direction. be done. Each mold 3,3
. . , there is a strand guide path indicated by a row of rollers 5.

The second mold 3, 3''... exhibits a bloom cross section.

Each of the molds 3, 3°... vibrates independently of each other, and the control of the molten steel level 6 of each mold 3.3°... is also independent from the control of the molten steel level of the other molds. The molten steel level is controlled by a plug 9 that more or less opens or closes the outflow lower of the tundish 1 to which the injection tube 8 that protrudes below the molten steel level in each mold 3, 3'' is attached.
respectively achieved by

Figure 3.4 shows the first,
This figure shows the continuous casting apparatus shown in Figure 2.

Instead of the molds 3, 3'... determined for casting strands with a bloom cross section, they are placed close to each other.

Two molds 1 () with billet cross-section, mounted and removably assembled in one common device part.

10' is provided. These two molds 10.10'
have a common connecting flange 11 which can be connected to a vertically vibrating flange 4 and thus vibrate in unison. 1
This type of mold assembled into individual equipment members is called a “twin”
Also called a mold.

Instead of the tundish shown in FIGS. 1 and 2, a pond tundish 12 is provided during billet casting. As is clear from FIG. 3, this tundish is collected in each of the two apparatus members, and each mold 10 of the billet cross-section mold 10.11)' is calibrated to produce a constant amount of water per unit time. It has an outflow nozzle 13 through which the molten steel flows and allows the molten steel to flow down into the mold. Each second mold 10'' of the molds 10, 10' assembled in each of the two apparatus parts has an injection tube 15 extending from above to below the molten steel level 14 of this mold 10'.

Each mold 10 is assembled in one apparatus member in close proximity to each other.
The strands 16 , 17 emerging from 10 ′ are pulled off in unison with the aid of driven pull-off rollers 18 of the roller bank 5 .

The roller bank 5 with the rollers 18, 19 has the illustrated width 20
Since the main strand has a bloom cross section located at the midpoint of the width of the roller row 5, the strand with a billet cross section coming out of the mold 10 and 10' collected in one device member is Support selectively. Therefore, the roller row 5 of the strand guide path does not need to be replaced even when changing from bloom casting to billet casting.

Each mold 10.10' has a molten steel level of 14 according to FIG.
．． A level detection device 121 for detecting the height of 23.
It is equipped with 22. Such level detection devices are known in the art (West German patent DE-B-2351.816, West German patent DE-C-1508955) and will not be described in detail here.

In the mold 10, which is supplied with molten steel by a calibrated outflow nozzle 13, the molten steel level 23, the measurement of which depends on the change in the withdrawal speed of the casting strand 16 emerging from this mold, is controlled by a level detection device 21. . A drive motor 24, which drives the roller 18 shown in FIG. 3, is connected to a level detection device 21 for this purpose via a control line 25. Mold 10 installed in one device member. The two strands 16° 17 coming out of the IQI are pulled out synchronously. Since the driven roller 18 extends over the two strands 16° 17 as described above, the second The molten steel level 14 of the mold 10' is necessarily varied by the above-mentioned control of the molten steel level 23 of the first mold 10. In order to adjust these and maintain the molten steel level 14 in the second mold 10' at the desired height, the value detected by the level detection device 22 attached to the second mold 10' is applied to this mold. This is related to the control of the plug 26 which regulates the inflow of molten steel. The plug 26 can be raised and lowered by a motor 27 in the direction of the double arrow 28, as is clear from FIG. Drive motor 27
is connected to the level detection device 22 via a control line 29. In this way, even though the two strands 16.17 are withdrawn synchronously, the molten steel level 1'4. ．． 23 can be held at the desired height independently of each other.

Instead of the plug 26, the flow of molten steel into the second mold 10' can be controlled by a sliding plug, in which case the drive motor for moving the sliding plug is connected to the level sensing device flt22. The calibrated outflow/spool 13 for the first mold 10 was closed by blocking or stopping the injection of molten steel, which could be realized by means of a plug or a sliding plug, not shown. However, these plugs and sliding plugs are not involved in the control of the molten steel level, but merely block the inflow of molten steel. The strands 16, 17 with the following billet cross-section are, according to the invention, so close together (their distance depends only on the wall thickness of the mold) that they bend due to their own radiant heat. In order to avoid this restricting the running of the strands 16.17, a radiant heat protection shield 30.31 is provided, as can be seen in FIG. That is, close to the bottom of the molds i o, i o' a first radiant heat protection shield is formed in the form of a widely guided fountain 32, which shield is located in the plane of symmetry 33 between the two strands 16, 17. It extends approximately to Furthermore, mold 10.10
Below ', a hollow cooling plate 34 through which water flows and its radiation heat protection shield 31 are arranged in the plane of symmetry 33.

A starting strand inserted during casting into a mold 3,3' with a bloom cross section is effectively used, and this starting strand has at its tip two starting strands protruding into the adjacent IJ mold 10, 10'. It is provided with an arm to which a strand head 36, 37 is fixed.

The adjustment of the molten steel level 14.23 in the mold 10, 10° during pouring is advantageously carried out manually.

A gas cutting device (not shown) for transverse cutting of the strands is equipped with a pendulum tip which simultaneously cuts two strands into pieces during casting of the strands with billet casting. The molds assembled in each of the two apparatus parts are effectively provided with individual cooling water inlet and cooling water outlet pipes that are independent of the adjacent molds.

[Brief explanation of the drawing]

Fig. 11 is a partially cutaway side view of a continuous casting device, Fig. 2 is a sectional view taken at n-11 of Fig. 1 of a continuous casting device for bloom casting, and Fig. 3 is a cross-sectional view of a continuous casting device for billet casting. 1 is a cross-sectional view taken along the line ■-■ in FIG. 1, and FIG. 4 is a perspective view of the apparatus shown in FIG. 3. 5... Roller row, 10.10'... Billet mold, 12... Tundish, 13... Outflow nozzle,
14゜23... Molten steel level, 16+17... Billet strand, 18... Driven roller, 21.22.
... Level detection device, 24.27 ... Drive motor, 2
S, 29...Control line, 26...Plug, 30.3
1... Radiation heat protection shield, 32... Fountain, 34.
...Cooling plate. FIG, 3 FIG, 2

Claims (6)

[Claims] (1) Continuous casting mold C1 with common tundish
0,10'), in particular two molds (10,10') having a billet cross-section and vibrating synchronously.
in the continuous casting molds (10, 10') of a multichamber continuous casting plant having two continuous casting molds, from which the strands (16, 17) are drawn by a synchronous prime mover (18° 24). A method for controlling the level of molten steel in one continuous casting mold (10).
23), the continuous casting mold (10,
Deviations of the liquid steel level (23) in said continuous casting mold (10) from the set value due to variations in the drawing speed of the entire casting strand (16, 17) emerging from the continuous casting mold (10') are compensated for, while other continuous The deviation of the molten steel level (14) in the casting mold (10') is the same as that of the other continuous casting mold (10').
') A method for controlling the level of molten steel, characterized in that the level of molten steel is controlled by changing the amount of molten steel flowing into the molten steel. (2) an apparatus for carrying out a method for controlling the level of molten steel, comprising at least two adjacent continuous casting molds (10, 10') with a common tundish (12);
In particular, it has a billet cross-section and is provided with a synchronous drive fi (18, 24) for the casting strands (16, 17) emerging from the mold (10, 10'), as well as said mold (1
Two synchronously vibrating continuous casting molds (10,10') with strand guideways arranged below (0,10')
), the continuous casting mold (10,1
0') is equipped with a molten steel level detection device (21, 22>) for detecting the molten steel level (14, 23), and from the tundish (12) to one of the molds (10) of the continuous casting molds (10, 10'). The inflow of molten steel is formed by free fall through the calibrated outflow nozzle (13), and the inflow of molten steel from the tundish (12) into the other mold (10') is caused by the plug (26) and the sliding plug. Controlled and calibrated outflow nozzle (1
3) The molten steel level detection device (21) of the mold (10) located below is connected to the drawing and roll (1) via the control line (25).
8), and the molten steel level detection device (22) of the other mold (10') is connected to the control device of the plug or sliding plug via connection wires (2). A device characterized by: (3) In the apparatus according to claim 2, the drawing rollers (18) of the strand guide path are connected to the casting strands (1G, 1) of the continuous casting molds (10, 10') arranged side by side. .7) A device characterized in that it is formed as a single piece extending over .7). (4) In the apparatus according to claim 2 or 3, the casting strand (t6, 17) is arranged along the open strand guide path (5) at right angles to the roller (one 18°). A device characterized in that a radiation heat protection shield (30°31) is provided at the top. 5. Device according to claim 4, characterized in that the radiation heat protection shield (31) is designed as a hollow cooling plate (34) through which water flows. (6) Device according to claim 4, characterized in that it is designed as a radiant heat protection shield (30) or as a widely dissipated fountain (32).